


The 7th Element

by RinkoStories



Series: The 7th Element [1]
Category: BanG Dream! (Anime), BanG Dream! Girl's Band Party! (Video Game)
Genre: Action, Circle, F/F, F/M, Thriller
Language: English
Status: Completed
Published: 2020-11-05
Updated: 2020-11-05
Packaged: 2021-03-09 04:27:21
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 5
Words: 3,159
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27398728
Author URL: https://archiveofourown.org/users/RinkoStories/pseuds/RinkoStories
Summary: Yukina is kidnapped by Trevor and his men, and he plays some missions with the girls in order to release her.
Relationships: Minato Yukina/Toyama Kasumi, Satou Masuki/Toyama Kasumi
Series: The 7th Element [1]
Series URL: https://archiveofourown.org/series/2001595
Kudos: 2





	1. Kidnapped

**Summary for the Chapter:**

> Early morning, Trevor and his men capture Yukina and her father.

In Shinjuku City, Tokyo, at 3:20 AM, Trevor Damme, Jack Bills, and his other men kidnap Yukina in her residence. They also kidnap her father inside.

6 hours later, Ran, during school, notices that Yukina is missing. She tries to find her, even with the Afterglow members and Lisa's help, but they don't find her. Ran then shares the message to her friends:  
「Attention, everyone. Yukina is missing. We tried to find her, but there is no sign of her. I don't know what even happened to her. She might be sick. I might check out her residence.」

Realizing this, those who read, including Kasumi, Aya, Kokoro, LAYER, and Mashiro, shocked. Ran asks them that after school, they go to Yukina's residence to see if she is sick. They both agree, and after school, they go to Yukina's residence, and the doors are all unlocked. They try to find her everywhere, but still, no sign of her inside.  
Kasumi: "Ran-chan, we're trying to find her... but she isn't there."  
Ran: "Well, if Yukina can be easily absent like that, I won't tolerate her. She can make a big mistake like tha-"  
(suddenly Kasumi's phone rings)  
Kasumi: "Moshimoshi?"  
Trevor: "Kasumi... There you are. You have been finding Yukina for hours. Well, she's with me. She and her father can't go anywhere... unless you follow my task."  
Kasumi: "What kind of task?"  
Trevor: "Please wait for around 15 minutes. We'll call you again soon."

Trevor and his men are ready to make an invasion, and they invade the southern shores in Chiba. They even advance a little bit to seize the apartment there. He takes 70 prisoners after the small invasion, including Yukina and her father (total 72). The police officers come in, but he confronts them.

Police officer: "You are violating a safety rule in this harbor. We will arrest you-"  
Trevor: "Shut up. I don't give a damn about what you said. We invaded this place for our own businesses. Disturbing our plans by any means will be killed. So you'd better get away and do nothing."

The police officers then go away. Trevor then sends a message to Kasumi.  
「Kasumi. Thanks for waiting. Now I know how you feel that you can't wait to see her released. However, those tasks I give to you must be accepted. Failure to comply will result on her death. First of all, I took her in Chiba, especially in the southern part. How long does it take to go there?」

Kasumi then sees the message and replies to him.  
Kasumi: 「Approximately 44 minutes.」  
Trevor: 「Incorrect. It's more than 44 minutes. But don't worry, it's just a question. Second, I took her in Kamogawa. How long?」  
Kasumi: 「Um... approximately 100 minutes through the Tokyo Bay Aqua Line. If not, 115 minutes.」  
Trevor: 「Fair enough. You will need to assemble your team to go to rescue her. I'll give you 120 minutes to go there, but with a few rules: One, do not cross Tokyo Bay Aqua Line. We will spectate your movements. Crossing there will lead to a destruction. Two, make sure you have enough time to act something in Chiba, because there will be no extensions, and you must use your time wisely. Good luck, and have fun dying.」

Kasumi then gathers her friends in Yukina's Residence.  
Aya: "Kasumi-chan... Are you sure about rescuing her with us?"  
Kasumi: "I'm sure. Whatever it costs."  
LAYER: "We, without struggle, are not us like now."  
Kasumi: "Same as we, without Yukina, are incomplete. We only have 6, but 7 is perfection! And the one to complete the miss is our mighty vocalist, Yukina-senpai!"  
Kokoro: "Well, let's go!!"  
Everyone: "Yay!!"

They pick up Yukina's car and Kasumi drives a car to Chiba.


	2. Getting Trevor

**Summary for the Chapter:**

> Kasumi and her friends go to Chiba to get Trevor and try to rescue Yukina.

On their way through the Chiba City, some of Trevor's men, disguised as police officers, know that Kasumi and her friends are on the way to meet him. They chase Kasumi by a car and shoot the car she's driving.  
Trevor's Man: "If you dare to cross this city, we will shoot you down!"  
Aya: "Kasumi-chan! Who are they?"  
Kasumi: "Those who dare to chase us are his men. The police knows what we are doing, so they surely won't hunt us down. Everyone, just survive from their attacks. I don't think we have any guns to repel them, but when you see them shooting at us, get down."  
LAYER: "There is a handgun inside her car. Mashiro found it. It has approximately... 4 bullets."  
Ran: "Use them wisely. Those bullets can hunt down chasers."

LAYER then shoots the chasers' front car tires and the front engine, causing the car to immobilize and explode, killing the chasers. They keep going, until they are able to reach Kamogawa in 100 minutes.

Kasumi: "We made it! We are able to reach this place, but hurry, we have no time to stick around!"

They go down from the car, and two other people come to Kasumi.  
People 1: "Are you Toyama-san from Tokyo? We think that he and his men capture hostages in the facility."  
Kasumi: "Yes, but where is it?"  
People 2: "Somewhere near here. You're very close to that place. By the way, there are some police officers who will give you guns during your mission."  
Kasumi: "Okay, thank you!"

The girls meet police officers to get the guns, and they go to the facility, seizing the entire building in 10 minutes, killing Trevor's men, but they didn't find the hostages.  
Aya: "We can't secure any hostages... It seems like we are wasting our time."  
Ran: "(*sigh*) Guess we'd better go somewhere precisely. If Yukina dies because of him, it is Kasumi's-"  
Kasumi: "Look! Over there! There is a prisoner ship!"  
LAYER: "He hijacked that ship like, 30 minutes ago."  
Kasumi: "What are we waiting for? Let's go!"

They then go to the prisoner ship, securing every places, killing every henchmen they encountered, and are able to meet Trevor 2 minutes before the deadline. The girls confront him.  
Trevor: "Heh heh heh. Finally, we're meeting each other. Well, Kasumi, tell me what do you need with the hostages."  
Kasumi: "I want them to be released! No one is not released!"  
Trevor: "Not so simple. To release every prisoners, it's not as simple as you thought. The key is what you are finding right now. But sadly, I don't bring a key-"  
Kasumi: "No keys? I got a gun from your dead man, you dimwit!" (draws a handgun)  
Trevor: "Stop! Don't shoot me! Promise me, I will release every hostages here, you can have your friend free. I promise."  
Kasumi: "Don't lie!"  
Trevor: "I'm not lying. Seriously. (moves backward as Kasumi is about to shoot him) If you dare to shoot me, you will never be able to release hostages. (slowly picks up the bomb detonator) If you want a key, then take this!" (draws a detonator and explodes the walls, revealing them as guards shooting the roof)  
Girls: [shocked]  
Trevor: "Arrest them. Take their guns, too. (the guards arrest the girls and take their guns) Now. I want to take every actions of you, seriously. No exceptions. Before I brief someone here... Gentlemen, bring those girls but Kasumi out from the ship. We'll move into somewhere else. But you two, stay here. (the guards bring out the girls but lets Kasumi in as she stands between two guards)

After confrontation, Kasumi, now with her hands chained in the back, is briefed by Trevor.  
Trevor: "Perfect. Kasumi, listen to me closely. Well, it is only you to figure out how to save your friends, even yourself. I don't even say you are unworthy, even in my heart I don't ever say insults to you. Because I'm not supposed to do that. It's really bad. At this moment, I lied on releasing hostages. I mean, one of the hostages will be kept as a hostage. You can release the hostages whatever you want, but one of them will still be taken. If you can still survive here, you're very lucky. But now, I'll leave the rest of the actions in this ship to my guards. Men, you know what to do in this ship. I'll see you later."

Trevor leaves, takes Yukina from the prison, and brings her with his men to the eastern Chiba.


	3. Returning Home

**Summary for the Chapter:**

> After her friends are captured by Trevor's men, Kasumi struggles herself to rescue hostages and return home.

After Trevor leaves, the guards bring Kasumi into the control room, where they are also about to detonate the bomb in the ship, hoping that they can kill her in a suicide bombing. While the guards are about to activate the bomb, Kasumi knocks out the first guard, and gets into a brawl with the guards, but when the second guard draws the handgun, Kasumi aims and shoots it into the first guard, killing him, then with her chains she is able to break the 2nd guard's neck.

Kasumi breaks free from the shackles by picking up the dead guards' keys and is able to disarm the bomb. She then releases every hostages, including Yukina's father, saying his thanks to her but warns her that Trevor has so many plans to threaten more people. Kasumi also apologizes to him about Yukina's condition, still being arrested.  
Yukina's Father: "Thank you for rescuing me, Toyama-san... I know she's still taken, but be advised that Trevor is a traitor from the beginning - he declares himself as an anti-nationalist, likes to make a deal with someone in order to fulfill his purposes, and most dangerously, he can escape any kinds of imprisonment."  
Kasumi: "That's so crazy... By the way, Sir, I apologize for Yukina... I tried my best to free her, but I wasn't able to free her from his grasp."  
Yukina's Father: "You still have a chance. I know they are still not killed. Let's go home."

After that they go outside the ship and she brings him home, while Kasumi goes to CHU2's mansion. Arriving there, she sits and apologizes to her friends about 'some of her friends are being taken by Trevor' via the message as MASKING comes to her.  
MASKING: "Hey, Kasumi. Nice work."  
Kasumi: "Masking! Hey there too. I apologize for your mate being taken. I know I did my best there, but... he can even fool us."  
MASKING: "Don't worry. They can feel how sad those friends are being taken. Now, relax, there are newspapers if you're interested. I can give some."  
Kasumi: "Thank you! By the way, do you have any rehearsals?"  
MASKING: "No, CHU2 said that there will be no rehearsals today. I just come here to look around."

MASKING then gives newspapers to Kasumi, and she goes outside and walk around, while Kasumi reads the newspaper until she felt asleep. That night, at 9 PM, MASKING wakes her up.  
MASKING: "Kasumi... Wake up."  
Kasumi: "(wakes up) Wha... What happened?"  
MASKING: "I can have you some coffee if you want. Because I got something interesting to you."  
Kasumi: "What is that?"  
MASKING: "Wait a minute. (brings a cup of coffee to her) Here's the coffee. I got some news to you... that the man you said, that had taken your friends into somewhere, is relocating their position in the eastern Chiba. And right now they have taken the eastern lab."  
Kasumi: (surprised) "Wha....? Man, I feel like I started to hate him now. I mean, I've had enough of his quotes and actions."  
MASKING: "Well, I think that place is the final one where he can run. Because every places around Chiba had been secured by the police officers to prevent further terrorism."  
Kasumi: "I hope his next question will be surely challenging. But I know he won't go anywhere. I'll invite my friends here, while I need you to accompany me to go there."  
MASKING: "Sure."

Kasumi then asks Arisa, Tomoe, Chisato, Lisa, Misaki, and Tsukushi to join her in her next mission. Tomoe, before leaving, offers Ako to join Kasumi in a rescue mission. Ako accepts. Arisa, before going to Kasumi, met Saaya in the pathway, and she gave Arisa some breads to share with girls. They then go to the facility in the eastern Chiba.


	4. The Lab

**Summary for the Chapter:**

> Kasumi and some of her friends go to the lab in the eastern Chiba to rescue the kidnapped girls. Meanwhile, Trevor makes a deal with her alone.

On their way to the facility, Arisa offers a bread if anyone wants. Ako wants that one, while the rest of them said that they are full. They are also having fun and talking to each other. 

Arriving at the eastern lab, they go down, and Kasumi walks to it. But, the message comes out from the entrance.  
Trevor: "Kasumi. Welcome back. I know you are there."  
Tomoe & Chisato: "T-Trevor?"  
Trevor: "Yes. Trevor Damme. A guy whose in the mission is to play ugly games. Now, listen to me. First, Kasumi will enter and meet me inside with the lights out. However, I will keep the lights on in the place where your friends are being held. Next, there are two rules that failure to comply will result in death of all hostages. So there are rules: One, your friends must not be brought in. I will only seek Kasumi's strength and determination. Two, no communications. No noises during the search, or my men will know those voices and quickly rush to kill you. Those are the rules. Also, there is a bomb where I will set a 25-minute countdown. You won't know how to disarm this bomb... unless you know the purpose of this bomb in this entire facility. Once the door is open, the countdown will begin, so make sure you use your time precisely and wisely. When she meets me, we'll make a deal. Are you ready to partake this mission, Kasumi?"  
Kasumi: "Yes! Whatever it costs! Just in case my friends will be released!"  
Trevor: "Well done. The door will open and the lights will out in 3... 2... 1." (opens the door, turns lights off, and starts the countdown timer)

Kasumi enters and picks up a combat knife and a hand gun with exactly 4 bullets on it. She manages to sneak against men with flashlights, even she can kill 2 of the men with the combat knife and steal their guns.

She is able to reach into the middle in 15 minutes, where the hostages are taken there. She meets Trevor and he makes a deal.  
Trevor: "Kasumi. We finally meet each other again. Now, you want to release your friends here. But you must make through one thing: A deal."  
Kasumi: "What kind of deals do you want?"  
Trevor: "Those deals are very hard to choose, but if you choose wisely, you will be able to break your limits. First, I will disarm the bomb, but your friends will stay and you will be killed. Second, I will release your friends, but the time bomb continues and you will be killed. Or any deals you wanted, just don't be long and don't be light."

Kasumi thinks around for around 20 seconds. At that moment, after seeing her friends imprisoned, her eyes are sparkling. She speaks bravely to him.  
Kasumi: "I'd better die here today... than just sitting around and let my friends suffer. My friends are invaluable; I can't risk losing them. I want my friends to be released, no exceptions."  
Trevor: "As you wish. You can have your own key. Now, it's my turn to deal a deal."

Trevor shoots Kasumi at her shoulders and legs, severely wounding her, then handcuffs her, leaves the room to plan an escape with his men, but leaves a key behind from his foot. The girls are shocked to see Kasumi presumed dead; but she is still able to get up.


	5. We're The 7th Element

**Summary for the Chapter:**

> Kasumi is still able to get up despite her wounds; she and her friends manage to escape the lab before it explodes.

7 minutes before the detonation, Kasumi is slowly waking up while she is regenerating. She picks up the key, releasing herself and the other friends. Her friends are relieved.  
Aya: "Kasumi-chan, thank you for saving us! You have made a decisive choice. Without you, we wouldn't be able to continue."  
LAYER: "Toyama-san... Thank you for your actions. Glad MASKING told you about it."  
Mashiro: "To- Toyama-san... Thank you..."  
Ran: "Kasumi, thank you very much. Sorry with my words before. I was supposed to be caring each othe-"  
Yukina: "Talk about it later! This isn't over! Look at the control room. They are escaping."  
(everyone gets shocked)  
Yukina: "The time is ticking. The bomb is about to explode."  
Kasumi: "I know that bomb can't be easily disarmed, right?"  
Yukina: "Yes. And the only way we can do is to block their way and we both can die here! Let's go!"

They both go to the control room and shut the door, while Trevor and Jack are about to escape through the door.  
Trevor: "Who the hell shut this goddamn door?"  
Jack: "Um... I think the girls, sir."  
Trevor: "Son of a b***h! How did my guns can't kill her?"  
Jack: "I don't know, I didn't see anything..."

4 minutes before explosion, Yukina picks up the chain, while the girls pick up the guns and start going down. They kill every men inside during their escape, including Jack. Those are Trevor's last men, and he can no longer reinforce any men. They have arrived into a ground floor, and Kasumi gets into an intense brawl with Trevor. He firstly gains an advantage, but Yukina quietly throws a chain, and Kasumi overcomes him with the chain. She can finally cuff him near the pole. Before the girls can escape Kasumi said to him:  
"We are the 7th element, and you are stuck-in-the-chain!"

The girls finally escape from the facility as the bomb explodes, destroying the lab and the falling debris from the top kill him.

They see the collapsing facility as they are finally reunited. They also hug each other and thanking Kasumi for her actions.  
Kokoro: "Kasumi! Thank you very much! You make us all happy! And that's why I never stop making a link... of smile!"  
Lisa: "Kasumi, thank you! Yukina is very glad to see you."  
Ako: "Kasumi ga daisukiii! I'm happy you saved Yukina-san!"  
Kasumi: "Thank you... but not only that. The girls are saved."  
Tomoe: "Kasumi, thank you! So we know what is your purpose that you invited us. Wanna some handshake?"  
Kasumi: "Tomoe-chan... I really love you!!" (shakes her hand)  
Arisa: ("Well, Kasumi has saved the girls... I'm really glad. I really love the girls keep shining.")  
Kasumi: "Arisaaaa-!! I love you too!!!' (hugs her)  
Arisa: "Gaah-! Get off me...! Aaaa... Chomama!!"  
(everyone laughs)

Meanwhile, a car from outside arrives and the driver offers the girls to go home with him.  
Driver: "Heh heh heh. So you are the girls who saved the day, right? I'm afraid you are so tired on waiting. I can offer you to go home. One car is not enough."  
Kasumi: "Sure! My accompanies will go home with you, but my best friends (vocalists) will be with me!"  
Driver: "Got it."

The girls then go home, as Kasumi's accompanies go home with the driver, while Kasumi and her remaining friends go home by Yukina's car.

**Author's Note:**

> Extra: This Is My Car
> 
> When Kasumi and the girls go home, Yukina realizes that it is her car.  
> Yukina: "Wait... This is my car, how do you use my car?"  
> Kasumi: "Well, I used your car to do a mission to save people, because we tried to find you in your house, but didn't find you. Also don't worry, no major damages!"  
> Yukina: "Thank God. I know what you were doing. Next time, don't forget to ask permission to someone about borrowing the car, okay?"  
> Kasumi: "I will!"
> 
> Everyone smiles.


End file.
